Rotation of the thrower-discus system and performance in discus throwing

The purpose of this study was to determine the effects of thrower-discus system rotation on performance in discus throwing. The resultant angular momentum of the thrower-discus system and direction cosines of the angular momentum vector were calculated from kinematic data at five critical instants of discus throwing for 28 female and 15 male elite discus throwers, and compared between their long and short trials in actual competition. Compared to short trials, elite female throwers' long trials had significantly less angular momentum at right foot takeoff and left foot takeoff (P ≤ 0.023), and significantly less top-to-left rotation at right foot takeoff, left foot takeoff, left foot touchdown, and release (P ≤ 0.007), and significantly greater right-to-left rotation at left foot touchdown and release (P ≤ 0.009) in long trials. Compared to their short trials, elite male throwers had significantly less top-to-left and top-to-front rotations at left foot touchdown (P ≤ 0.042), and significantly less total angular momentum at release (P = 0.043) in long trials. Elite discus throwers should control the amount of rotations of the thrower-discus system to reduce the top-to-left roll of the discus during the flight to extend the aerodynamic distance.

Influence of two kinematics on canal transportation and centering ability of WaveOne Gold and One Curve files

This research examines canal transportation and centering ability of single-file systems when operated in continuous rotation or reciprocation. Sixty J-shaped resin blocks were used. The specimens were divided into two main groups (n = 30). Then, based on the motion used to operate the instruments, each group was subdivided into two subgroups (n = 15). Group A1: One Curve/rotation, Group A2: One Curve/clockwise reciprocation, Group B1: WaveOne Gold/Reciprocation, Group B2: WaveOne Gold/counter-clockwise rotation. Pre- and post-instrumentation images were obtained using digital microscope. Canal transportation was measured at five levels. A non-significant difference (p > 0.05) resulted between two motions at all levels. However, group A1 showed significantly less transportation at levels 3 and 4 (p ≤ 0.05), also more centered preparation at level 4 (p ≤ 0.05) than group B1. Within the limitations of this study, the apical transportation and centering ability of single-file systems are unaffected by different kinematics.

3D prediction of curve progression in adolescent idiopathic scoliosis based on biplanar radiological reconstruction

Aims

This systematic review aims to identify 3D predictors derived from biplanar reconstruction, and to describe current methods for improving curve prediction in patients with mild adolescent idiopathic scoliosis.

Methods

A comprehensive search was conducted by three independent investigators on MEDLINE, PubMed, Web of Science, and Cochrane Library. Search terms included "adolescent idiopathic scoliosis","3D", and "progression". The inclusion and exclusion criteria were carefully defined to include clinical studies. Risk of bias was assessed with the Quality in Prognostic Studies tool (QUIPS) and Appraisal tool for Cross-Sectional Studies (AXIS), and level of evidence for each predictor was rated with the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. In all, 915 publications were identified, with 377 articles subjected to full-text screening; overall, 31 articles were included.

Results

Torsion index (TI) and apical vertebral rotation (AVR) were identified as accurate predictors of curve progression in early visits. Initial TI > 3.7° and AVR > 5.8° were predictive of curve progression. Thoracic hypokyphosis was inconsistently observed in progressive curves with weak evidence. While sagittal wedging was observed in mild curves, there is insufficient evidence for its correlation with curve progression. In curves with initial Cobb angle < 25°, Cobb angle was a poor predictor for future curve progression. Prediction accuracy was improved by incorporating serial reconstructions in stepwise layers. However, a lack of post-hoc analysis was identified in studies involving geometrical models.

Conclusion

For patients with mild curves, TI and AVR were identified as predictors of curve progression, with TI > 3.7° and AVR > 5.8° found to be important thresholds. Cobb angle acts as a poor predictor in mild curves, and more investigations are required to assess thoracic kyphosis and wedging as predictors. Cumulative reconstruction of radiographs improves prediction accuracy. Comprehensive analysis between progressive and non-progressive curves is recommended to extract meaningful thresholds for clinical prognostication.

Condition Monitoring of Railway Bridges Using Vehicle Pitch to Detect Scour

This study proposes the new condition monitoring concept of using features in the measured rotation, or 'pitch' signal, of a crossing vehicle as an indicator of the presence of foundation scour in a bridge. The concept is explored through two-dimensional vehicle-bridge interaction modelling, with a reduction in stiffness under a pier used to represent the effects of scour. A train consisting of three 10-degree-of-freedom carriages cross the model on a profiled train track, each train varying slightly in terms of mass and velocity. An analysis of the pitch of the train carriages can clearly identify when scour is present. The concept is further tested in a scaled laboratory experiment consisting of a tractor-trailer crossing a four-span simply supported bridge on piers. The foundation support is represented by four springs under each pier, which can be replaced with springs of a reduced stiffness to mimic the effect of scour. The laboratory model also consistently shows a divergence in vehicle pitch between healthy and scoured bridge states.

What Do Patients Report Regarding Their Real-World Function Following Concurrent Arthrodesis of the First Tarsometatarsal and First Metatarsophalangeal Joints

First metatarsal phalangeal joint and the first Tarsometatarsal arthrodesis have both been used for deformity correction and treatment of pain and arthritis. Concomitant arthrodesis of the first metatarsophalangeal and first tarsometatarsal joints (Double First Ray Arthrodesis) has rarely been described. We surveyed 29 patients who underwent double first-ray arthrodesis for primary or revision correction of hallux valgus. A custom questionnaire was used to assess their activities of daily living and sports activity at a mean follow-up of 19.6 months (median 18.4 months). Secondary endpoints were return to activity, deformity correction, and arthrodesis healing rate. The primary outcomes showed an excellent return to activities of daily living with 96.6% of patients capable of walking as much as they liked after surgery at a normal pace. About 96.6% reported they felt that their surgery was successful, they had no pain, and the loss of motion at the joint fusion sites did not affect their ability to perform daily activities. Protected walking in a fracture boot was initiated at a mean (SD) of 9.8 (9.9) days. Return to an athletic shoe occurred at a mean (SD) of 44.2 (11.7) days. Full unrestricted activity was at a mean (SD) of 105.2 (19.3) days with 65% of the patient group reporting that their recovery was easier than expected. There was 1 nonunion and no other complications. This data set supports the hypothesis that patients undergoing double first-ray arthrodesis can return to activities of daily living and sports with and low complication rate.

Spatially Conserved Spiral Wave Activity During Human Atrial Fibrillation

BACKGROUND

Atrial fibrillation is the most common cardiac arrhythmia in the world and increases the risk for stroke and morbidity. During atrial fibrillation, the electric activation fronts are no longer coherently propagating through the tissue and, instead, show rotational activity, consistent with spiral wave activation, focal activity, collision, or partial versions of these spatial patterns. An unexplained phenomenon is that although simulations of cardiac models abundantly demonstrate spiral waves, clinical recordings often show only intermittent spiral wave activity.

METHODS

In silico data were generated using simulations in which spiral waves were continuously created and annihilated and in simulations in which a spiral wave was intermittently trapped at a heterogeneity. Clinically, spatio-temporal activation maps were constructed using 60 s recordings from a 64 electrode catheter within the atrium of N=34 patients (n=24 persistent atrial fibrillation). The location of clockwise and counterclockwise rotating spiral waves was quantified and all intervals during which these spiral waves were present were determined. For each interval, the angle of rotation as a function of time was computed and used to determine whether the spiral wave returned in step or changed phase at the start of each interval.

RESULTS

In both simulations, spiral waves did not come back in phase and were out of step." In contrast, spiral waves returned in step in the majority (68%; P=0.05) of patients. Thus, the intermittently observed rotational activity in these patients is due to a temporally and spatially conserved spiral wave and not due to ones that are newly created at the onset of each interval.

CONCLUSIONS

Intermittency of spiral wave activity represents conserved spiral wave activity of long, but interrupted duration or transient spiral activity, in the majority of patients. This finding could have important ramifications for identifying clinically important forms of atrial fibrillation and in guiding treatment.

Clinical outcomes of stromal lenticule rotation to correct mixed astigmatism

PURPOSE

To describe a stromal lenticule rotation surgical technique to correct mixed astigmatism and evaluate the initial clinical outcomes of this innovative approach.

METHODS

This retrospective case series included five eyes from five patients with mixed astigmatism that underwent intrastromal lenticule rotation surgery. The eyes were evaluated for uncorrected visual acuity, corrected distance visual acuity, manifest refraction, central corneal thickness, corneal volume, anterior and posterior K readings, and corneal higher order aberrations (HOAs) (including total HOAs, spherical aberrations, coma, and trefoil) using the Scheimpflug-Placido topographer before and 3 months after surgery. The corneal epithelium and stroma were imaged using anterior segment optical coherence tomography (AS-OCT) postoperatively. A paired-sample t-test was used to analyse the data.

RESULTS

Clinical improvement was found in the uncorrected distance visual acuity (0.64 ± 0.11 logMAR vs. 0.20 ± 0.17 logMAR) and spherical and cylindrical diopters (D) (+2.65 ± 1.32 D vs. -0.05 ± 0.51 D and -4.95 ± 0.94 D vs. -1.10 ± 0.78 D, respectively). Anterior flat keratometry readings showed a steep trend (40.65 ± 1.24 D vs. 42.73 ± 0.63 D). Anterior corneal astigmatism decreased from 4.50 ± 0.55 D to 2.05 ± 0.73 D. According to the AS-OCT images, no significant epithelial remodelling was observed postoperatively. Although no significant differences were found among the increased corneal HOAs, the coma and trefoil changed much more than spherical aberrations 3 months postoperatively.

CONCLUSIONS

The results for these five eyes suggest that the autologous stromal lenticule rotation technique is safe and effective; it may be an economical and feasible surgical option for correcting mixed astigmatism.

Age-Related Changes in Temporal Binding Involving Auditory and Vestibular Inputs

Maintaining balance involves the combination of sensory signals from the visual, vestibular, proprioceptive, and auditory systems. However, physical and biological constraints ensure that these signals are perceived slightly asynchronously. The brain only recognizes them as simultaneous when they occur within a period of time called the temporal binding window (TBW). Aging can prolong the TBW, leading to temporal uncertainty during multisensory integration. This effect might contribute to imbalance in the elderly but has not been examined with respect to vestibular inputs. Here, we compared the vestibular-related TBW in 13 younger and 12 older subjects undergoing 0.5 Hz sinusoidal rotations about the earth-vertical axis. An alternating dichotic auditory stimulus was presented at the same frequency but with the phase varied to determine the temporal range over which the two stimuli were perceived as simultaneous at least 75% of the time, defined as the TBW. The mean TBW among younger subjects was 286 ms (SEM ± 56 ms) and among older subjects was 560 ms (SEM ± 52 ms). TBW was related to vestibular sensitivity among younger but not older subjects, suggesting that a prolonged TBW could be a mechanism for imbalance in the elderly person independent of changes in peripheral vestibular function.

Nonadherence of Polyurethane Implants: A Retrospective Cohort Study

Background  Biointegration of polyurethane (PU) implants providing their stable position years after surgery ensures predictable results of breast augmentation and reconstruction almost eliminating implant factor as a cause of complications. However, in rare cases PU implants appear to be not connected to the surrounding tissues. The aim of the study was to determine the incidence of PU implant nonadherence after primary breast augmentations and augmentation mastopexies with dual plane implant position, to analyze possible causes, and to propose preventive measures and treatment possibilities of this complication. Methods  The results of primary aesthetic surgeries in 333 patients with dual plane PU implant placement were analyzed. Patients were evaluated clinically, and pictures and videos taken in different periods after the surgery were compared. Particular attention was given to the changes in implant position and the appearance of asymmetries over time. Results  PU implant nonadherence was found in seven patients. It can be divided into primary and secondary and may be complete or partial. Primary nonadherence was found in two cases (0.6%), and secondary in five (1.5%) cases. Possible influencing factors could have been traumatic surgical technique, seroma, hematoma, or physical trauma. The average follow-up was 33 months (1 month-15 years). Conclusion  Biointegration is mandatory for the long-term predictable results with PU implants. PU implant nonadherence leads to implant malposition and may cause typical complications connected to non-PU implants. Improvements in surgical maneuvers, manufacturing process, and weight reduction of the implant may be beneficial for the stability of the results. Level of Evidence  V.

Multi-Planar Expansion of the Coronal Plane Alignment of the Knee Classification? A Computed Tomographic Study Indicates No Significant Correlation With Alignment Parameters in Other Planes

BACKGROUND

The Coronal Plane Alignment of the Knee (CPAK) classification categorizes knee phenotypes based on constitutional limb alignment (arithmetic hip-knee-ankle angle or aHKA) and joint line obliquity (JLO). This study aimed to determine if sagittal and rotational knee alignments vary among CPAK types in order to establish whether this classification should be expanded beyond coronal plane assessment.

METHODS

Coronal, sagittal, and rotational alignment measurements were made and CPAK types were calculated from computed tomographic data of 437 patients (509 knees) who underwent robotic-assisted total knee arthroplasty (TKA). Differences in femoral, tibial, and tibio-femoral angular measurements were compared across CPAK types, and correlations were made to aHKA and JLO. Nonparametric and linear regression tests were used to analyze between-type differences.

RESULTS

There were no differences in tibial slope or femoral rotational measures across CPAK phenotypes. However, CPAK Type III knees had a greater tibio-femoral rotation mean difference than CPAK Type I, II, IV, and V knees (P < .05). We also found increased femoral flexion in Type I knees when compared to Type VI knees (P = .01). The aHKA had a weak correlation with femoral flexion angle, and JLO had a weak correlation with femoral posterior condylar axis to tibial antero-posterior axis angle.

CONCLUSION

Few clinically important differences in sagittal and rotational alignments were found between CPAK types, indicating that CPAK phenotype has little correlation to 3-dimensional alignment characteristics. Need for an expansion of the CPAK classification beyond coronal plane alignment is not supported from these results.

Warping Torsion in Sandwich Panels: Analyzing the Structural Behavior through Experimental and Numerical Studies

Recently, there has been a growing interest in the use of sandwich panels that, beyond handling well-known bending stress, can withstand torsional stresses. This is particularly relevant for wall applications when the panels are equipped with photovoltaic or supplemental curtain wall modules. This research article presents a detailed exploration of the structural behavior of eccentrically loaded sandwich panels, with a specific focus on warping torsion. Experimental and numerical studies were conducted on polyisocyanurate (PU) core sandwich panels, commonly employed in building envelopes. These studies involved various dimensions and material properties, while omitting longitudinal joints. The experimental study provided essential insights and validated the numerical model in ANSYS. Enabling parametric variation, the numerical analysis extends the analysis beyond the experimental scope. Results revealed a high degree of correlation between experimental, numerical, and analytical solutions, regarding the rotation, as well as the normal and shear stress of the panel. Confirming the general applicability of warping torsion in sandwich panels with certain limitations, the study contributes valuable data for applications and design of eccentrically loaded sandwich panels, laying the foundation for potential engineering calculation methods.

Association between trunk rotation and pelvic rotation in adolescents with idiopathic scoliosis

BACKGROUND

Previous studies have suggested an association between pelvic rotation (PR) and scoliotic deformity in severe adolescent idiopathic scoliosis (AIS), but none have investigated this relationship in mild to moderate AIS.

OBJECTIVE

To investigate the relationship between PR and trunk rotation in mild to moderate AIS.

METHODS

This was a case-control study. The cases were 32 AIS patients with PR in the opposite direction to the thoracic curve, and the controls were 32 AIS patients with PR in the same direction as the thoracic curve. All patients were assessed with the Adams forwards bend test. Type II trunk rotation was selected as exposure. Logistic regression was used to estimate the association between PR direction and types of trunk rotation while accounting for confounders. Multiple linear regression was used to analyse the relationships between PR magnitude and the angle of trunk rotation (ATR).

RESULTS

Logistic regression showed an unadjusted OR of 9.13 (95% CI 2.92-28.50, P< 0.001), and adjustment for sex and Cobb angle only slightly changed the OR (adjusted OR, 8.23; 95% CI, 2.51-27.01; P= 0.001). The concave/convex ratio was associated with ATR measurements in both cases (β=-0.379; P= 0.030) and controls (β=-0.468, P= 0.008).

CONCLUSION

An association was found between PR and trunk rotation, which may help achieve more effective physiotherapy in mild to moderate AIS.

Diode Laser versus Conventional Surgical Circumferential Supracrestal Fiberotomy in Preventing Relapse of Orthodontically Derotated Teeth: A Randomised Control Trial

Objective

To evaluate the effectiveness of a diode laser (810 nm) for circumferential supracrestal fiberotomy compared with conventional surgical circumferential supracrestal fiberotomy in preventing rotational relapse in orthodontically treated cases.

Methods

Seventy-six patients (age range from 18-25 years) with mandibular crowding ranging between 5-8 mm and rotation >10˚ (from the individualized arch form) treated non-extraction with a straight wire appliance (McLaughlin, Bennet, Trevisi; 0.022 inch) prescription were selected for the study. The patients were randomly allocated into 3 groups of 22 patients each: Group 1 (Control group-No circumferential supracrestal fiberotomy), Group 2 (Conventional circumferential supracrestal fiberotomy), and Group 3 (diode laser circumferential supracrestal fiberotomy). After leveling and alignment up to "0.019x0.025" stainless steel wire, the arch wire was removed for a period of 1 month. Impressions were made and the poured casts were scanned. The 3D models (.STL files) were evaluated for changes in the irregularity index and rotational relapse.

Results

One-way ANOVA and post-hoc Tukey's test were used for data analysis. Group 1 (Control group) showed greater relapse in both irregularity index and rotation angulations in comparison with Groups 2 and 3, which was statistically significant (p<0.001). There was no statistically significant difference in irregularity index and rotational relapse between Group 2 and Group 3 (p=0.35 for irregularity index, and p=0.41 for rotational relapse).

Conclusion

The control group showed significantly more relapse than both circumferential supracrestal fiberotomy groups. Both conventional and diode laser circumferential supracrestal fiberotomy decreased the relapse tendency.

Self-Rotation of Electrothermally Responsive Liquid Crystal Elastomer-Based Turntable in Steady-State Circuits

Self-excited motions, characterized by their ability to harness energy from a consistent environment and self-regulate, exhibit significant potential in micro-devices, autonomous robotics, sensor technology, and energy generation. This study introduces an innovative turntable system based on an electrothermally responsive liquid crystal elastomer (LCE). This system facilitates self-rotation within a steady-state circuit. Employing an electrothermal LCE model, we have modeled and numerically analyzed the nonlinear dynamics of an LCE-rope within steady-state circuits, utilizing the four-order Runge-Kutta method for calculations. The numerical results reveal the emergence of two distinct motion patterns in the turntable system under steady-state conditions: a self-rotation pattern and a static pattern. The self-rotation is initiated when the system's absorbed energy surpasses the energy lost due to damping effects. Furthermore, this paper delves into the critical conditions necessary for initiating self-rotation and examines the influence of various key dimensionless parameters on the system's rotation amplitude and frequency. These parameters include gravitational acceleration, the initial position of the mass ball, elastic stiffness of the LCE and spring, limiting temperature, heating zone angle, thermal shrinkage coefficient, and damping factor. Our computational findings establish that these parameters exert a modulatory impact on the rotation amplitude and period. This research enhances the understanding of self-excited motions and offers promising avenues for applications in energy harvesting, monitoring, soft robotics, medical devices, and micro- and nano-devices.

Rotation of the uterus to obtain a lower transverse incision in the posterior wall in a cesarean section: a case report and literature review

OBJECTIVE

To demonstrate that cesarean section with a transverse incision at the lower posterior wall of the uterus is suitable for some special obstetric cases.

CASE REPORT

A 35-year-old primigravida with a previous surgical history of laparoscopic myomectomy underwent elective cesarean section at 39 weeks and 2 days of gestation. During surgery, there were severe pelvic adhesions and engorged vessels on the anterior wall. Considering safety, we rotated the uterus 180 degrees and made a lower transverse incision on the posterior wall. The infant was healthy and the patient had no complications.

CONCLUSIONS

A low transverse incision in the posterior uterine wall is safe and effective when the incision of the anterior wall encounters a dilemma, especially in patients with severe pelvic adhesions. We recommended this approach should be done in selected cases.

Sustained deviation of torsional eye position associated with transient semicircular canal stimulation

BACKGROUND

Vestibular stimulation causes postural unsteadiness accompanied by a sensation of tilt.

AIMS/OBJECTIVES

The mechanism of the sensation of tilt needs to be assessed by accurate calculation of the rotational axis of torsional eye position under various vestibular stimulations.

MATERIAL AND METHODS

Twenty-two healthy subjects participated in the study. Thirteen subjects underwent bilateral vestibular stimulation by on-axis yaw rotation under various head positions, and eighteen subjects underwent unilateral vestibular stimulation by caloric irrigation under various head positions. Listing's Plane was plotted for the eye movement data obtained by three-dimensional video-oculography.

RESULTS

The offset of Listing's Plane showed sustained deviation of torsional eye position that was more prominent in head positions that stimulated lateral semicircular canals more than vertical semicircular canals. There was a less prominent and directionally reversed offset in head positions that stimulated vertical canals more than lateral semicircular canals.

CONCLUSION AND SIGNIFICANCE

The sustained torsional eye position was validated by accurate assessment using Listing's Plane. The mechanism behind the deviation may be due to a combination of multiple anatomical components within the vestibular apparatus, with potentially stronger influence from lateral semicircular canals.

Intraoperative Augmented Rotation and Circumferential Strain Compensate for Reduction of Left Ventricular Longitudinal Function After On-Pump CABG Surgery

OBJECTIVES

Left ventricular (LV) longitudinal function is reduced after on-pump coronary artery bypass grafting (CABG), while global LV function often is preserved. There are only limited data on the underlying compensatory mechanism. Therefore, the authors aimed to describe intraoperative changes of LV contractile pattern by myocardial strain analysis.

DESIGN

A prospective observational study.

SETTING

At a single university hospital.

PARTICIPANTS

A total of 30 patients scheduled for isolated on-pump CABG with an uneventful intraoperative course and preoperative preserved LV and RV function, sinus rhythm, without more-than-mild heart valve disease, or elevated pulmonary pressure.

INTERVENTIONS

Transesophageal echocardiography was performed after induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3). Echocardiographic evaluation was performed under stable hemodynamics, in sinus rhythm or atrial pacing, and vasopressor support with norepinephrine ≤0.1 µg/kg/min.

MEASUREMENTS AND MAIN RESULTS

EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway) was used for analysis of 2-dimensional (2D) and 3-dimensional (3D) LV ejection fraction (EF), LV global longitudinal strain (GLS), LV global circumferential strain (GCS), LV global radial strain (GRS), LV apical rotation (aRot), LV basal rotation (bRot), and LV twist. Strain analysis was feasible in all included patients after termination of cardiopulmonary bypass (T2). Although there were no significant differences in the values of conventional echocardiographic parameters during the intraoperative interval, GLS deteriorated significantly after CABG compared to pre-bypass assessment (T1 v T2, -13.4% ± 2.9 v -11.8% ± 2.9; p = 0.007). GCS improved significantly after surgery (T1 v T2, -19.4% (IQR -17.1% to -21.2%) v -22.8% (IQR -21.1% to -24.7%); p < 0.001) as well as aRot (T1 v T2, -9.7° (IQR -7.1° to -14.1°) v -14.5° (IQR -12.1° to -17.1°); p < 0.001), bRot (T1 v T2, 5.1° (IQR 3.8°-6.7°) v 7.2° (IQR 5.6°-8.2°); p = 0.02), and twist (T1 v T2, 15.8° (IQR 11.7°-19.4°) v 21.6° (IQR 19.2°-25.1°); p < 0.001), while GRS remained unchanged. There were no significant changes in the values of GLS, GCS, GRS, aRot, bRot, or twist, as well as in the values of 2D and 3D LV EF before and after sternal closure (T2 v T3).

CONCLUSION

Beyond evaluation of longitudinal LV strain, measurements of circumferential and radial strain, as well as LV rotation and twist mechanics, were feasible in the intraoperative course of this study. Reduction of longitudinal function after on-pump CABG was compensated intraoperatively by improvement of GCS and rotation in the authors' group of patients. Perioperative assessment of GCS, GRS, as well as rotation and twist, might provide deeper insight into perioperative changes of cardiac mechanics.

Accumulated Hard Tissue Debris and Root Canal Shaping Profiles Following Instrumentation with Gentlefile, One Curve, and Reciproc Blue

INTRODUCTION

This laboratory study aimed to evaluate the accumulated hard tissue debris (AHTD) and shaping performance following root canal instrumentation with a novel stainless steel rotary system (Gentlefile; MedicNRG, Kibbutz Afikim, Israel) compared with two single-file nickel-titanium instruments of different kinematics through micro-computed tomography (micro-CT) analysis.

METHODS

Thirty isthmus-containing mesial roots of human mandibular molars with a curvature of 15°-35° were scanned with micro-CT at an isotropic resolution of 12 μm and randomly assigned to three groups (n = 10) according to the instruments used for canal preparation: Gentlefile (GF; #23/.04), One Curve (OC; #25/.06; Micro-Mega, Besancon, France), and Reciproc Blue R25 (RB; #25/.08; VDW, Munich, Germany). The AHTD, unprepared canal surface area, volume changes, surface area changes, and transportation were evaluated by comparing preoperative and postoperative micro-CT images. In addition, the time required for canal preparation was recorded. Data were statistically analyzed using the one-way analysis of variance (ANOVA) test or the Kruskal-Wallis test at a significance level of 5%.

RESULTS

No significant differences were observed in the percentage of AHTD or in the unprepared canal surface area between the three groups (P > .05). The RB group demonstrated a significantly greater percentage increase in volume and surface area than the GF group (P < .05). The GF and OC groups showed significantly less transportation at 3 mm from the apex than the RB group (P < .001). The OC group required significantly less time for instrumentation than the RB and GF groups (P < .05).

CONCLUSIONS

Instrumentation with GF (#23/.04), OC, and RB yielded similar levels of AHTD and unprepared surface area in isthmus-containing curved canals. GF achieved this with less dentin removal and apical transportation, at the expense of a longer preparation time.

Left ventricular rotational mechanics and left ventricular volumes: is there a relationship in healthy adults?-three-dimensional speckle-tracking echocardiography-derived insights from the MAGYAR-Healthy Study

Background

Left ventricular (LV) rotational mechanics play a crucial role in LV pump function by strengthening and improving its efficacy. Dependence of LV rotational parameters on left atrial volumes has already been demonstrated. The evaluation of the effect of LV rotational mechanics on LV volumes was purposed in a population of healthy subjects by three-dimensional speckle-tracking echocardiography (STE).

Methods

The study comprised 175 healthy subjects with a mean age of 32.8±12.2 years (79 males). All subjects underwent a complete physical examination, laboratory assessments, standard 12-lead electrocardiography and two-dimensional Doppler and three-dimensional STE, the results of these examinations were within the normal range.

Results

Increased basal LV rotation was associated with increased LV volume measured in end-systole and impaired LV ejection fraction. Increased apical LV rotation was associated with reduced LV volumes assessed in end-diastole and in end-systole and increased ejection fraction of the LV. Elevated basal LV rotation showed associations with increased LV mass. In case of increasing basal LV rotation, apical LV rotation showed a decreasing tendency and LV twist showed a tendency of increasing. Similarly, lower basal LV rotation and increased LV twist were seen with increasing apical LV rotation. Increasing LV end-diastolic volume was associated with increasing LV volume measured in end-systole and preserved ejection fraction of the LV. Increasing LV end-systolic volume was associated with increasing LV end-diastolic volume and reduction of LV ejection fraction. Increasing LV volumes were associated with increasing LV mass. While increased LV volumes were associated with reduced apical LV rotation and twist, basal LV rotation did not show significant changes.

Conclusions

LV rotational mechanics are strongly associated with LV volumes in healthy adults suggesting its volume-dependence.

Rotation of liquid-preserved artificial insemination doses on roller benches affects sperm quality during storage in stallions

Appropriate stallion semen handling is of great importance in equine artificial insemination (AI) industry. Optimal treatment of AI doses is aiming for best sperm preservation by excluding strong environmental influences and adding media that favour sperm survival. One method widely used in stallion sperm handling is the rotation of liquid-preserved semen samples on roller benches during storage. As previous studies in boars give rise to the fact that rotation should not be considered beneficial for spermatozoa anymore, the present study investigated the influence of continuous rotation of diluted stallion AI portions on sperm quality. Ejaculates (n = 15) were collected at a German AI centre and diluted with the two extenders EquiPlus and Gent (Minitüb GmbH) to a final concentration of 50 × 106  sperm/mL. Afterwards, samples were placed separately on roller benches at 5°C in the dark, obtaining a rotation frequency of 5 revolutions per minute (rpm) and 36 rpm for four consecutive days following a split-sample design. Both groups were analysed daily in comparison to a control group (0 rpm) with an extended spectrum of spermatological methods including computer-assisted sperm analysis and flow cytometry. Statistical analyses were based on the calculation of generalized linear mixed models for each sperm parameter. The research revealed a decrease in sperm quality parameters of rotated samples compared to non-rotated control groups, visible in total sperm motility (p < .001), decreased thermo-resistance (p < .01) and a drop in pH (p < .001). Interestingly, no differences (p > .05) were detected between rotation frequencies of 5 and 36 rpm. We conclude that the fertilizing capacity of stallion semen was negatively affected by rotation during storage in vitro, irrespective of the rotation frequency. Further studies need to investigate whether field fertility in horses is similarly affected by semen rotation on roller benches in vivo.

What Do Patients Report Regarding Their Real-World Function Following Triplane Metatarsophalangeal Joint Arthrodesis for Hallux Valgus?

First metatarsal phalangeal (MTP) joint arthrodesis has been employed for decades for pain related to arthritis and other associated abnormalities. Despite the commonality of the procedure there continues to be questions regarding functional expectations following the procedure especially when employed for correction of hallux valgus deformity. We surveyed 60 patients who had a tri plane MTP joint arthrodesis at mean 28.4 months (median 27.8) regarding their activities of daily living and sports activity through a direct conversation. Secondary endpoints assessed were return to activity, deformity correction and arthrodesis healing rate based on chart review and weightbearing radiographs. The primary outcomes showed robust return to all activities of daily living with 96.7% able to walk without restrictions and or pain, 98.3% were able to walk at a normal pace and 95% responded that loss of motion of their big toe did not affect their daily function. Regarding return to sports all patients that participated in sports before surgery resumed participation after with a trend toward increased sports activity. Early return to walking in a fracture boot was noted in this cohort at mean 4.1 days, return to athletic shoe at mean 6.3 weeks and full unrestricted activity at mean 13.3 weeks with no non-unions identified on radiographic or clinical exam. Deformity correction of the typical components of hallux valgus deformity was similar to previously published studies. This data set supports the hypothesis that patients undergoing first MTP joint arthrodesis can expect rapid and full return to activities of daily living and sports with a low complication rate.

The Hip Center Rule Can be Used to Decide if Measured Pelvic Incidence is Accurate

STUDY DESIGN

Simulation study.

OBJECTIVE

Pelvic incidence (PI) should be considered during surgical planning. The ideal patient position with both hip centers perfectly aligned for a lateral radiograph is rarely obtained. It has been suggested that a radiograph with axial and coronal rotation up to 20° is acceptable to obtain a measured PI within 6 degrees of the actual PI. We seek to: (1) evaluate the effect of variations in PI and patient malpositioning on measured vs true PI, and (2) determine whether the presence of one hip center within the bony acetabular rim of the contralateral hip can serve as a simple clinical decision rule on the accuracy of measured PI.

METHODS

Published anthropometric three-dimensional pelvic landmark coordinates were used in this study. Radiographic projections were generated using linear algebra for combinations of axial and coronal rotation from -20° to +20°. True and measured PIs were compared.

RESULTS

Rotation to 20° cannot be uniformly accepted as decision rule. Pelvises with higher PIs are more sensitive to malpositioning with greater PI deviation with smaller amounts of rotation. Diagnostic performance of the hip center rule demonstrated a sensitivity of 25.58% and a specificity of 100.00%.

CONCLUSIONS

Rather than assessing the quality of radiographs for PI measurement by magnitude of malpositioning, we recommend clinicians use the "hip center rule." As long as at least one hip center is contained within the bony acetabular rim of the contralateral hip, there is high confidence that measured PI will be within 6° of true PI.

Impacts of different Nickel-Titanium rotary and reciprocating root canal preparation systems on the amount of apically extruded debris

This study aimed to evaluate the amount of apically extruded debris caused by different NiTi files. One hundred mandibular premolars were included in this study. The specimens were divided into five groups (n = 20): (i) TruNatomy, (ii) WaveOne Gold, (iii) 2Shape, (iv) ProTaper Next and (v) Reciproc Blue. The extruded debris was collected into preweighed Eppendorf tubes. These tubes were weighed again, and the net weight of debris was calculated. Data were statistically analysed, and the significance level was set at 5%. The least amount of extruded debris was observed in the TruNatomy group (p < 0.05). Statistically significant differences were not found among (iii), (iv) and (v) groups (p > 0.05). However, these groups resulted in significantly higher amounts of debris when compared to (i) and (ii) groups (p < 0.05). The results lead us to conclude that all instrumentation systems caused apical extrusion of debris at varying weights.

Assessment of the psychomotor fitness level of cadet pilots after a 6-month flight training period - pilot study

Objectives

The aim of the study was to investigate the impact of 6-month aviation practice on the improvement of physical fitness and cognitive abilities of cadet pilots.

Materials and methods

Twenty cadet pilots (men) with an average age of 22 from the Polish Air Force Academy were tested. Two tests of effort were conducted: before (test I) and after (test II) practical flights. Test of physical effort relyed on the number of rotations of looping accomplished. When performing rotations on looping, in tests I and II, the percentage level of task performance was assessed using a diagnostic and training device. Tasks for the exerciser were sent wirelessly to the glasses from the operator’s position. The heart rate (HR) and blood pressure were measured with a camera-type Microlife AG.

Results

In test II, there was a statistically significant improvement in the percentage of task completion (p &lt; 0.01) and an insignificant improvement in the performance of rotations on looping compared to test I. After Test I and II demonstrated a statistically significant increase in HR and systolic blood pressure when compared to before test values. Test II illustrated a significant decrease in systolic blood pressure after effort (p &lt; 0.05) with regard to test I.

Conclusion

The study showed that cadet aviation practice ameliorated their physical fitness and cognitive skills, as well as helped to diminish their situational stress, which resulted in a decrease in systolic blood pressure after test II.

Surgical Approach for RSA has Little or no Influence on Scapular Inclination and Glenoid Baseplate Tilt Relative to the Horizontal

Purpose

Determine whether reverse shoulder arthroplasty (RSA) glenoid baseplate tilt is influenced by surgical approach and/or associated with functional scores.

Methods

In total, 501 shoulders (483 patients) who underwent RSA, by anterosuperior (AS, n = 88) or deltopectoral (DP, n = 413) approach. Preoperative and immediate postoperative anteroposterior and scapular Y-view radiographs were used to measure: Inclination of the supraspinatus fossa's floor relative to the horizontal (Sigma angle), inclination of the glenoid fossa line (or glenoid baseplate surface) relative to the horizontal (beta-h angle) or to the supraspinatus fossa's floor (beta-s angle).

Results

Sigma and beta-h were significantly greater for shoulders operated by DP approach, both preoperatively (P < .001, P = .002) and postoperatively (P = .004, P < .001), but net change was not significantly different (P = .501, P = .742). Conversely, beta-s was significantly greater for shoulders operated by DP approach, only postoperatively (P = .042), but there were no significant differences in either preoperative angles (P = .580) or net change thereof (P = .528).

Conclusion

Beta-s was slightly but significantly greater for shoulders operated by DP approach, while beta-h and sigma depended primarily on preoperative scapular inclination and glenoid tilt, rather than on surgical approach. At a minimum of 2 years following RSA, neither constant scores nor net improvements thereof were significantly associated with any of the angles.

Level of evidence

IV, case series.

Silver Ions Inhibit Bacterial Movement and Stall Flagellar Motor

Silver (Ag) in different forms has been gaining broad attention due to its antimicrobial activities and the increasing resistance of bacteria to commonly prescribed antibiotics. However, various aspects of the antimicrobial mechanism of Ag have not been understood, including how Ag affects bacterial motility, a factor intimately related to bacterial virulence. Here, we report our study on how Ag⁺ ions affect the motility of E. coli bacteria using swimming, tethering, and rotation assays. We observed that the bacteria slowed down dramatically by >70% when subjected to Ag⁺ ions, providing direct evidence that Ag⁺ ions inhibit the motility of bacteria. In addition, through tethering and rotation assays, we monitored the rotation of flagellar motors and observed that the tumbling/pausing frequency of bacteria increased significantly by 77% in the presence of Ag⁺ ions. Furthermore, we analyzed the results from the tethering assay using the hidden Markov model (HMM) and found that Ag⁺ ions decreased bacterial tumbling/pausing-to-running transition rate significantly by 75%. The results suggest that the rotation of bacterial flagellar motors was stalled by Ag⁺ ions. This work provided a new quantitative understanding of the mechanism of Ag-based antimicrobial agents in bacterial motility.

Effect of long-term rotation on astigmatism following EVO-toric intraocular collamer lens implantation

Objective

To evaluate the effect of long-term rotation on astigmatism following Evolution-toric intraocular collamer lens (EVO-TICL) implantation.

Methods

Forty eyes of 22 patients were enrolled in this prospective study. Visual acuity, refractive parameters, and axial position of the EVO-TICL by OPD-Scan III aberrometer were measured preoperatively, 1 month and 3 years postoperatively.

Results

Last visit, the safety index was 1.32 ± 0.15 and the efficacy index was 1.01 ± 0.23. The best-fitting curve of the attempted versus achieved correction was y = 0.9751x + 0.001. The mean spherical equivalent (SE) decreased from -8.94 ± 2.72D preoperatively to 0.06 ± 0.24D and - 0.36 ± 0.46D 1 month and 3 years postoperatively, respectively. The mean target and surgical induced astigmatism were 1.55 ± 0.61D and 1.67 ± 0.94D 3 years postoperatively. The average expected axis of the TICL was-1.15 ± 9.07 (-21-19°). One month and 3 years postoperatively, the average actual axis was -0.70 ± 9.86 (-20-20°) and - 0.35 ± 11.72 (-25-30°), respectively. The absolute rotation of the TICL was 3.70 ± 4.42 (0-22°) and 6.00 ± 6.70 (0-32°) 1 month and 3 years postoperatively, respectively (p < 0.001). The expected astigmatism was -0.10 ± 0.12D, and the mean actual astigmatism was -0.21 ± 0.30D and - 0.44 ± 0.45D 1 month and 3 years postoperatively, respectively. The mean absolute rotation without postoperative astigmatism was 3.73 ± 2.69 (0-9°) and 1.67 ± 1.66 (0-5°) for low (<2D) and high (≥2D) astigmatic TICL, respectively (p < 0.05).

Conclusion

EVO-TICL implantation is safe and effective, with good predictability and stability. OPD-Scan is a fast device to detect the axial position of the TICL without mydriasis, and the axial position is relatively stable in the long term postoperatively. A slight rotation of low-astigmatic TICL may not cause postoperative astigmatism, whereas rotation of the high-astigmatic TICL may cause it.

Using a 3D Navigation Template to Increase the Accuracy of Thoracic Pedicle Screws in Patients with Scoliosis

This study compares the accuracy and safety of pedicle screw placement using a 3D navigation template with the free-hand fluoroscopy technique in scoliotic patients. Fifteen scoliotic patients were recruited and divided into a template group (eight cases) and a free-hand group (seven cases). All patients received posterior corrective surgeries, and the pedicle screw was placed using a 3D navigation template or a free-hand technique. After surgery, the positions of the pedicle screws were evaluated using CT. A total of 264 pedicle screws were implanted in 15 patients. Both the two techniques were found to achieve satisfactory safety of screw insertion in scoliotic patients (89.9% vs. 90.5%). In the thoracic region, the 3D navigation template was able to achieve a much higher accuracy of screw than the free-hand technique (75.3% vs. 60.4%). In the two groups, the accuracy rates on the convex side were slightly higher than on the concave side, while no significance was seen. In terms of rotational vertebrae, no significant differences were seen in Grades I or II vertebrae between the two groups. In conclusion, the 3D navigation template technique significantly increased the accuracy of thoracic pedicle screw placement, which held great potential for extensively clinical application.

Ascertaining the Career Intentions of Medical Students (AIMS) in the United Kingdom Post Graduation: Protocol for a Mixed Methods Study

BACKGROUND

Among doctors in the United Kingdom, there is growing sentiment regarding delaying specialist training, emigrating to practice medicine abroad, or leaving the profession altogether. This trend may have substantial implications for the future of the profession in the United Kingdom. The extent to which this sentiment is also present in the medical student population is not well understood.

OBJECTIVE

Our primary outcome is to determine current medical students' career intentions after graduation and upon completing the foundation program and to establish the motivations behind these intentions. Secondary outcomes include determining which, if any, demographic factors alter the propensity to pursue different career paths available to a medical graduate, determining which specialties medical students plan on pursuing, and understanding current views on the prospect of working in the National Health Service (NHS).

METHODS

The Ascertaining the Career Intentions of Medical Students (AIMS) study is a national, multi-institution, and cross-sectional study in which all medical students at all medical schools in the United Kingdom are eligible to participate. It was administered via a novel, mixed methods, and web-based questionnaire and disseminated through a collaborative network of approximately 200 students recruited for this purpose. Both quantitative and thematic analyses will be performed.

RESULTS

The study was launched nationally on January 16, 2023. Data collection was closed on March 27, 2023, and data analysis has commenced. The results are expected to be available later in the year.

CONCLUSIONS

Doctors' career satisfaction within the NHS is a well-researched topic; however, there is a shortage of high-powered studies that are able to offer insight into medical students' outlook on their future careers. It is anticipated that the results of this study will bring clarity to this issue. Identified areas of improvement in medical training or within the NHS could be targeted to improve doctors' working conditions and help retain medical graduates. Results may also aid future workforce-planning efforts.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/45992.

Soft-Tissue Tensor Total Knee Arthroplasty with Anatomic Implants

Background and Objectives: Total knee arthroplasty (TKA) is the most effective treatment method for end-stage osteoarthritis. One of the most important aspects of this surgery is adequate implant positioning, as it guarantees the desired outcome of restoring limb biomechanics. Surgical technique is being continuously improved along with hardware development. There are two novel devices designed to help establish proper femoral component rotation: soft-tissue tensor and robotic-assisted TKA (RATKA). This study compared the femoral component rotation achieved with the use of three methods: RATKA, soft tissue tensioner and the conventional measured-resection technique, all of them utilizing anatomical design prosthesis components. Materials and Methods: A total of 139 patients diagnosed with end-stage osteoarthritis underwent total knee arthroplasty between December 2020 and June 2021. After the surgery, they were divided into three groups depending on procedure technique and implant type: Persona (Zimmer Biomet) + Fuzion Balancer, RATKA + Journey II BCS or conventional TKA + Persona/Journey. Postoperatively, a computed tomography examination was performed in order to measure femoral component rotation. All three groups were compared independently during statistical analysis. Fisher's exact, Kruskal-Wallis and Dwass-Steel-Crichtlow-Fligner tests were used for particular calculations. Results: Statistically significant differences in femoral component rotation between groups were noticed. However, in terms of values other than 0° in external rotation, no significant variance was revealed. Conclusions: Additional total knee arthroplasty instruments seem to improve the outcomes of the surgery, providing better component positioning than in the conventional measured-resection technique based only on bone landmarks.

Optically Driven Rotation of Exciton-Polariton Condensates

The rotational response of quantum condensed fluids is strikingly distinct from rotating classical fluids, especially notable for the excitation and ordering of quantized vortex ensembles. Although widely studied in conservative systems, the dynamics of rotating open-dissipative superfluids such as exciton-polariton condensates remains largely unexplored, as it requires high-frequency rotation while avoiding resonantly driving the condensate. We create a rotating polariton condensate at gigahertz frequencies by off-resonantly pumping with a rotating optical stirrer composed of the time-dependent interference of two frequency-offset, structured laser modes. Acquisition of angular momentum exceeding the critical 1ℏ/particle is directly measured, accompanied by the deterministic nucleation and capture of quantized vortices with a handedness controlled by the pump rotation direction. The demonstration of controlled optical rotation of a spontaneously formed polariton condensate enables new opportunities for the study of open dissipative superfluidity, ordering of non-Hermitian quantized vortex matter, and topological states in a highly nonlinear, photonic platform.

Methods of measuring distal canine movement and rotation- A review

This article provides an overview of the various methods for measuring distal canine movement and rotation during retraction. Various databases, including PubMed Central, Science Direct, Wiley Online Library, the Cochrane Library, Textbooks, Google Scholar, and Research Gate, and a manual search up until September 2022, were used to search for various methods of measuring distal canine movement and rotation during retraction. After excluding the duplicate articles, the papers explaining these techniques were included. Four significant techniques were identified. The digital method with 3D superimposition is the safest, most accurate, and most accessible of the methods reviewed.

Dynamics of liquids with high viscosity contrast in unevenly rotating Hele-Shaw cell

The paper is devoted to the experimental study of the dynamics of an interface between two liquids with high viscosity contrast filling a vertical, circular narrow gap rotating about a horizontal axis at a speed modulated by librations. The equilibrium shape and stability of the interphase boundary are considered. In the absence of librations, under the action of the centrifugal force the boundary has an axisymmetric shape. At librations, at certain frequency ratios, the interface loses its axisymmetric position: in the cavity reference frame, it is displaced in the radial direction. It is theoretically shown that the discovered phenomenon is explained by the average action of gravity; the results of experiments and theory are consistent. The experiments reveal that with an increase in the modulation amplitude the circular interface loses stability in a threshold manner: an azimuthally periodic relief, quasi-stationary in the cavity frame, emerges. This is associated with the Kelvin-Helmholtz instability due to tangential oscillations of the less viscous liquid near the interface. A dimensionless parameter that determines the stability of the interface is obtained in the limit of high dimensionless libration frequency. The stability threshold increases with the decrease in the dimensionless frequency. This article is part of the theme issue 'New trends in pattern formation and nonlinear dynamics of extended systems'.

Examination of Thoracic and Lumbosacral Spine Guide for Neurosurgery Residents

Background

This paper outlines a summary of examination techniques for the thoracic and lumbosacral spine. It starts with observation, palpation and a range of movements followed by various special tests to identify thoracic and lumbosacral spine pathology.

Methods

Bedside instruments used include a measuring tape, scoliometer and back range of motion instrument (BROM II).

Discussion

Back flexion-extension, lateral flexion and rotation were assessed with bedside instruments. This would aid in increasing the accuracy and precision of objective measurement while conducting a clinical examination to determine the back range motion. Specific tests were used to localise specific anatomical locations and identify the spine pathology that can help the clinician to diagnose and treat the disease.

Treatment for cephalic arch stenosis with cephalic vein to external jugular vein bridging graft

AIM

Percutaneous transluminal angioplasty or cephalic vein transposition to the axillary vein is mainly used for treatment of cephalic arch stenosis, a common complication of brachiocephalic fistulas. However, the results of such interventions have been disappointing.

METHODS

We used a polytetrafluoroethylene prosthesis with a 6 mm diameter to bridge the cephalic vein and the ipsilateral external jugular vein, and successfully created a new drainage outlet and established immediate restoration of flow through brachiocephalic fistulas.

RESULTS

This surgery allowed the cephalic venous arch and subclavian vein, which are vulnerable to stenosis, to be bypassed altogether and the puncture segment could be elongated by about 20 cm.

CONCLUSION

It is a safe and effective alternative to traditional methods of treatment for cephalic arche stenosis.

Questioning rotary functionality in the bacterial flagellar system and proposing a murburn model for motility

Bacterial flagellar system (BFS) was the primary example of a purported 'rotary-motor' functionality in a natural assembly. This mandates the translation of a circular motion of components inside into a linear displacement of the cell body outside, which is supposedly orchestrated with the following features of the BFS: (i) A chemical/electrical differential generates proton motive force (pmf, including a trans-membrane potential, TMP), which is electro-mechanically transduced by inward movement of protons via BFS. (ii) Membrane-bound proteins of BFS serve as stators and the slender filament acts as an external propeller, culminating into a hook-rod that pierces the membrane to connect to a 'broader assembly of deterministically movable rotor'. We had disclaimed the purported pmf/TMP-based respiratory/photosynthetic physiology involving Complex V, which was also perceived as a 'rotary machine' earlier. We pointed out that the murburn redox logic was operative therein. We pursue the following similar perspectives in BFS-context: (i) Low probability for the evolutionary attainment of an ordered/synchronized teaming of about two dozen types of proteins (assembled across five-seven distinct phases) towards the singular agendum of rotary motility. (ii) Vital redox activity (not the gambit of pmf/TMP!) powers the molecular and macroscopic activities of cells, including flagella. (iii) Flagellar movement is noted even in ambiances lacking/countering the directionality mandates sought by pmf/TMP. (iv) Structural features of BFS lack component(s) capable of harnessing/achieving pmf/TMP and functional rotation. A viable murburn model for conversion of molecular/biochemical activity into macroscopic/mechanical outcomes is proposed herein for understanding BFS-assisted motility. HIGHLIGHTSThe motor-like functionalism of bacterial flagellar system (BFS) is analyzedProton/Ion-differential based powering of BFS is unviable in bacteriaUncouplers-sponsored effects were misinterpreted, resulting in a detour in BFS researchThese findings mandate new explanation for nano-bio-mechanical movements in BFSA minimalist murburn model for the bacterial flagella-aided movement is proposedCommunicated by Ramaswamy H. Sarma.

Axial rotation and pain are associated with facet joint osteoarthritis in Adolescent Idiopathic Scoliosis

OBJECTIVE

Facet joints are crucial for spinal stability and develop premature osteoarthritis in patients with adolescent idiopathic scoliosis (AIS). Here, we evaluated the association between facet joint cartilage and subchondral bone homeostasis, perceived back pain and 3-dimensional spinal deformity to understand better the role of facet joint degeneration in AIS progression and pain.

METHOD

Cartilage and bone osteoarthritic states of AIS facet joint surgical samples were characterized using histological OARSI scoring, visual morphological grading and μCT analysis, respectively. Back pain was self-reported using a numerical rating scale and expressed relative to the location on the patient's back. The scoliotic curves from our patient cohort were digitally reconstructed using biplanar radiographs and the eOS system (EOS imaging). The deformity was then reduced to 3 intervertebral angles (coronal, sagittal and axial) for each pair of bilateral facet joints. Statistical associations between the intervertebral angles, osteoarthritis parameters and pain intensity were performed using the Spearman method and Friedman test.

RESULTS

Facet joint cartilage degeneration was associated with decreased subchondral bone volume and quality. Most importantly, asymmetrical, and overall degeneration of facet joints was strongly correlated to intervertebral axial rotation. Additionally, kyphotic intervertebral segments in the sagittal plane were good predictors of increased facet joint degeneration and back pain.

CONCLUSION

Facet joint degeneration is associated with axial deformity, kyphotic intervertebral angle and back pain intensity in AIS. These results suggest that facet joints are important features to consider for rotational instability in AIS spines and related disease progression and perceived back pain.

CPR quality with rotation of every 1 versus 2 minutes as characteristics of rescuers: A randomized crossover simulation study

BACKGROUND

Fatigue and rotation time are key factors affecting the quality of cardiopulmonary resuscitation (CPR). This study aimed to investigate the effects of rotation time on CPR duration, and sex on chest compression quality.

METHODS

In this randomized crossover simulation study, we enrolled 100 paramedic students stratified by sex and randomly grouped into 28 male and 22 female pairs. In the 2- and 1-minute scenarios, 2 participants performed CPR for 20 minutes with a rotation cycle of 2 minutes and 1 minute, respectively. After taking a break, they changed over and performed CPR again for 20 minutes. The switching of roles was performed with the students positioned on opposite sides of the mannequin. For chest compression quality, a set was defined as CPR performed by 1 pair in a 2-minute scenario for 4 minutes. The quality of CPR in each set was compared between the 2 groups.

RESULTS

The 1-minute group showed significantly higher chest compression depth than the 2-minute group (54.0 [51.5-57.0] vs 52.5 [48.5-56.5] mm, P = .001, respectively). The female 2-minute group showed decreased chest compression depth over time, and the 1-minute group showed significantly increased chest compression depth during all sets except the 2nd set (54.0 [51.9-55.1] vs 50.5 [48.5-53.8] mm [P = .030], 52.3 [49.4-54.5] vs 50.8 [47.0-53.1] mm [P = .080], 52.8 [49.8-54.5] vs 48.8 [45.4-51.6] mm [P = .002], 51.5 [48.5-53.3] vs 48.3 [44.5-50.6] mm [P = .004], and 50.8 [48.9-54.1] vs 47.5 [44.6-50.1] mm [P = .001], respectively). The fatigue scores in the 2-minute group were significantly higher during sets 4 and 5 than those in the 1-minute group.

CONCLUSION

When rescuer fatigue increases during prolonged CPR owing to their physical strength and skill levels, the rotation of rescuers every minute would be helpful in maintaining high-quality CPR.

What Do Patients Report Regarding Their Real-World Function Following Triplane Metatarsophalangeal Joint Arthrodesis for Hallux Valgus?

First metatarsalphalangeal (MTP) joint arthrodesis has been employed for decades for pain related to arthritis and other associated abnormalities. Despite the commonality of the procedure there continues to be questions regarding functional expectations following the procedure especially when employed for correction of hallux valgus deformity. We surveyed 60 patients who had a triplane MTP joint arthrodesis at mean 28.4 months (median 27.8) regarding their activities of daily living and sports activity through a direct conversation. Secondary endpoints assessed were return to activity, deformity correction and arthrodesis healing rate based on chart review and weightbearing radiographs. The primary outcomes showed robust return to all activities of daily living with 97% able to walk without restrictions and or pain, 98% were able to walk at a normal pace and 95% responded that loss of motion of their big toe did not affect their daily function. Regarding return to sports all patients that participated in sports before surgery resumed participation after with a trend toward increased sports activity. Early return to walking in a fracture boot was noted in this cohort at mean 4.1 days, return to athletic shoe at mean 6.3 weeks and full unrestricted activity at mean 13.3 weeks with no non-unions identified on radiographic or clinical exam. Deformity correction of the typical components of hallux valgus deformity was similar to previously published studies. This data set supports the hypothesis that patients undergoing first MTP joint arthrodesis can expect rapid and full return to activities of daily living and sports with a low complication rate.

E-cadherin-dependent coordinated epithelial rotation on a two-dimensional discoidal pattern

In vivo, cells collectively migrate in a variety of developmental and pathological contexts. Coordinated epithelial rotation represents a unique type of collective cell migrations, which has been modeled in vitro under spatially confined conditions. Although it is known that the coordinated rotation depends on intercellular interactions, the contribution of E-cadherin, a major cell-cell adhesion molecule, has not been directly addressed on two-dimensional (2D) confined substrates. Here, using well-controlled fibronectin-coated surfaces, we tracked and compared the migratory behaviors of MDCK cells expressing or lacking E-cadherin. We observed that wild-type MDCK II cells exhibited persistent and coordinated rotations on discoidal patterns, while E-cadherin knockout cells migrated in a less coordinated manner without large-scale rotation. Our comparison of the collective dynamics between these two cell types revealed a series of changes in migratory behavior caused by the loss of E-cadherin, including a decreased global migration speed, less regularity in quantified coordination, and increased average density of topological defects. Taken together, these data demonstrate that spontaneous initiation of collective epithelial rotations depends on E-cadherin under 2D discoidal confinements.

RunScribe Sacral Gait Lab™ Validation for Measuring Pelvic Kinematics during Human Locomotion at Different Speeds

Optoelectronic motion capture systems are considered the gold standard for measuring walking and running kinematics parameters. However, these systems prerequisites are not feasible for practitioners as they entail a laboratory environment and time to process and calculate the data. Therefore, this study aims to evaluate the validity of the three-sensor RunScribe Sacral Gait Lab™ inertial measurement unit (IMU) in measuring pelvic kinematics in terms of vertical oscillation, tilt, obliquity, rotational range of motion, and the maximum angular rates during walking and running on a treadmill. Pelvic kinematic parameters were measured simultaneously using an eight-camera motion analysis system (Qualisys Medical AB, GÖTEBORG, Sweden) and the three-sensor RunScribe Sacral Gait Lab™ (Scribe Lab. Inc. San Francisco, CA, USA) in a sample of 16 healthy young adults. An acceptable level of agreement was considered if the following criteria were met: low bias and SEE (<0.2 times the between-subject differences SD), almost perfect (r > 0.90), and good reliability (ICC > 0.81). The results obtained reveal that the three-sensor RunScribe Sacral Gait Lab™ IMU did not reach the validity criteria established for any of the variables and velocities tested. The results obtained therefore show significant differences between the systems for the pelvic kinematic parameters measured during both walking and running.

Dependence of Left Ventricular Rotational Mechanics on Left Atrial Volumes in Non-Smoker Healthy Adults: Analysis Based on the Three-Dimensional Speckle-Tracking Echocardiographic MAGYAR-Healthy Study

Introduction: As has been established, the left ventricle (LV) and the left atrium (LA) form an organic unit of the left heart; however, little is known about the dependence of LV rotational parameters on LA volumes, even in healthy circumstances. Therefore, the present study aimed to assess the associations between basal and apical LV rotations and LA volumes and volume-based functional properties throughout the cardiac cycle in healthy adults by three-dimensional speckle-tracking echocardiography. Methods: The present study comprised 167 healthy adults (age: 33.4 ± 12.6 years, 77 males) with normally directed LV rotational mechanics. All subjects underwent complete two-dimensional Doppler echocardiography with three-dimensional speckle-tracking echocardiography (3DSTE)-derived data acquisition. The 3DSTE-derived LA volumes and LV rotational parameters were determined at a later date. Results: An increasing end-systolic maximum LA volume (Vmax) was associated with increasing pre-atrial-contraction early (VpreA) and minimum end-diastolic (Vmin) LA volumes, and all stroke volumes were increased as well. Systolic basal left ventricular rotation (LVrot) was highest in the case of the highest systolic Vmax and early-diastolic VpreA. Apical LVrot did not show obvious associations with any increasing LA volumes. The highest systolic basal LVrot was associated with significantly increased diastolic VpreA and Vmin. Reduced diastolic LA volumes (VpreA, Vmin) were seen in the case of increased apical LVrot. An increasing basal LVrot was associated with the tendentious lowering of the apical LVrot and the significant elevation of LV twist. Similarly, an increasing apical LVrot was associated with the tendentious lowering of basal LVrot and the significant elevation of LV twist. Conclusions: Strong associations and adaptations between 3DSTE-derived LA volumes throughout the cardiac cycle and LV rotational mechanics were evidenced, even in healthy circumstances.

Mechanical Janus Structures by Soft-Hard Material Integration

Engineering Janus structures that possess anisotropic features in functions have attracted growing attention for a wide range of applications in sensors, catalysis, and biomedicine, and are yet usually designed at the nanoscale with distinct physical or chemical functionalities in their opposite sides. Inspired by the seamless integration of soft and hard materials in biological structures, here a mechanical Janus structure composed of soft and hard materials with a dramatic difference in mechanical properties at an additively manufacturable macroscale is presented. In the combination of extensive experimental, theoretical, and computational studies, the design principle of soft-hard materials integrated mechanical Janus structures is established and their unique rotation mechanism is addressed. The systematic studies of assembling the Janus structure units into superstructures with well-ordered organizations by programming the local rotations are further shown, providing a direct route of designing superstructures by leveraging mechanical Janus structures with unique soft-hard material integration. Applications are conducted to demonstrate the features and functionalities of assembled superstructures with local ordered organizations in regulating and filtering acoustic wave propagations, thereby providing exemplification applications of mechanical Janus design in functional structures and devices.

Reniform Nematode Management Using Winter Crop Rotation and Residue Incorporation Methods in Greenhouse Experiments

Rotylenchulus reniformis (reniform nematode, RN) is an important pathogen in cotton production. Cultural practices such as crop rotation and biofumigation-management of soil pathogens by biocidal compounds from crop residues-may help manage RN. The objective of this study was to evaluate the efficacy of winter crops for RN management through combinations of rotation and crop residue incorporation in a cotton greenhouse experiment. A total of 10 treatments were evaluated in soil inoculated with RN: three winter crops (carinata, oat, or hairy vetch) grown in rotation with no shoot organic matter (OM) incorporated (1-3), fresh shoot OM incorporated (4-6), or dry shoot OM incorporated (7-9), and a fallow control (10). Roots were re-incorporated in all treatments except fallow. Subsequently, cotton was grown. Oat and fallow were better rotation crops to lower soil RN abundances at winter crop termination than hairy vetch and carinata. After the OM incorporation treatments and cotton growth, oat was generally more effective at managing RN in cotton than carinata or hairy vetch. Within each crop, incorporation treatment generally did not affect RN management. Cotton growth was not consistently affected by the treatments.

Left Ventricular "Longitudinal Rotation" and Conduction Abnormalities-A New Outlook on Dyssynchrony

BACKGROUND

The complete left bundle branch block (CLBBB) results in ventricular dyssynchrony and a reduction in systolic and diastolic efficiency. We noticed a distinct clockwise rotation of the left ventricle (LV) in patients with CLBBB ("longitudinal rotation").

AIM

The aim of this study was to quantify the "longitudinal rotation" of the LV in patients with CLBBB in comparison to patients with normal conduction or complete right bundle branch block (CRBBB).

METHODS

Sixty consecutive patients with normal QRS, CRBBB, or CLBBB were included. Stored raw data DICOM 2D apical-4 chambers view images cine clips were analyzed using EchoPac plugin version 203 (GE Vingmed Ultrasound AS, Horten, Norway). In EchoPac-Q-Analysis, 2D strain application was selected. Instead of apical view algorithms, the SAX-MV (short axis-mitral valve level) algorithm was selected for analysis. A closed loop endocardial contour was drawn to initiate the analysis. The "posterior" segment (representing the mitral valve) was excluded before finalizing the analysis. Longitudinal rotation direction, peak angle, and time-to-peak rotation were recorded.

RESULTS

All patients with CLBBB (n = 21) had clockwise longitudinal rotation with mean four chamber peak rotation angle of -3.9 ± 2.4°. This rotation is significantly larger than in patients with normal QRS (-1.4 ± 3°, p = 0.005) and CRBBB (0.1 ± 2.2°, p = 0.00001). Clockwise rotation was found to be correlated to QRS duration in patients with the non-RBBB pattern. The angle of rotation was not associated with a lower ejection fraction or the presence of regional wall abnormalities.

CONCLUSIONS

Significant clockwise longitudinal rotation was found in CLBBB patients compared to normal QRS or CRBBB patients using speckle-tracking echocardiography.

Rotation of Multiple Single-Gene Transgenic Crops Did Not Slow the Evolution of Resistance to Cry1F or Cry1Ie in Ostrinia furnacalis

A common strategy for delaying the evolution of resistance to transgenic crops that produce insecticidal proteins from Bacillus thuringiensis is to ensure that insect pests are exposed to multiple toxins with different mechanisms of action (MoAs). This can take the form of planting crops in a rotation pattern when different crops expressing single toxins are available on the market. The efficacy of a rotation strategy is reliant on mathematical models based on biological assumptions. Here, we designed laboratory evolution experiments to test whether Bt-based insecticidal proteins with different MoAs used in rotation could delay resistance from developing in Asian corn borer (ACB), Ostrinia furnacalis. We investigated the proteins Cry1Ab, Cry1F, and Cry1Ie, which are widely utilized for commercial insect control. We found that rotation of multiple toxins did not slow the evolution of resistance to Cry1F or Cry1Ie. Furthermore, the evolution of ACB to the Cry1Ab toxin develops faster when Cry1F or Cry1Ie is present, as compared to Cry1Ab exposure only. Our results suggest that toxins used in a rotation fashion do not work as an effective strategy in delaying ACB resistance evolution to Cry toxins over one-toxin exposure. Our result highlights the need to better understand the biological factors leading to insecticidal protein resistance and to develop IRM strategies against target insects.

Comparison of translational and rotational modes towards passive rheology of the cytoplasm of MCF-7 cells using optical tweezers

A colloidal particle placed inside the cell cytoplasm is enmeshed within a network of cytoskeletal fibres immersed in the cytosolic fluid. The translational mode is believed to yield different rheological parameters than the rotational mode, given that these modes stretch the fibers differently. We compare the parameters for Michigan Cancer Foundation-7 (MCF-7) cells in this manuscript and find that the results are well comparable to each other. At low values of 0 Hz viscosity, the rotational and translational viscoelasticity matches well. However, discrepancies appear at higher values which may indicate that the cytoskeletal modes involved in rotation and translation of the particle are getting invoked. We also show that the 0 Hz viscosity increases as the cell ages under the conditions of constant room temperature of 25^°C on the sample chamber.

From 2D projections to the 3D rotation matrix: an attempt for finding a machine learning approach for the efficient evaluation of mechanical joining elements in X-ray computed tomography volume data

Destructive and predominantly manual procedures are commonly used in the automotive industry for the testing of mechanical joints, such as rivets or screws. Combining X-ray computed tomography (CT) and machine learning (ML) bears the potential of a non-destructive and largely automated methodology. Assuming the desired result is a comprehensible and documentable evaluation, three basic steps need to be automatized: First, a joint must be detected and identified as such in a CT scan of the joined parts. Second, the detected region containing the joint is rotated to a predefined orientation. Third, key measures in cross-sections from the newly oriented joint are dimensioned and documented. This work deals only with the second step, the rotation. On the one hand, we present a methodology for creating a well-curated data set for the contextual machine learning application. On the other, we evaluate its performance on the well-known ResNet50. More concretely, we investigate if it is possible for a deep convolutional neural network (CNN) to learn the respective rotation matrix from three volume projections that are perpendicular to each other. Two scenarios are investigated: In one scenario we assume that future data that is presented to the network has similar rivet demographics to historic data. We therefore do not employ hold-out sets for the network evaluation. In the other scenario we assume the opposite and therefore evaluating the networks performance with hold-out sets. We show that from a machine learning point of view, a CNN like ResNet50 is well able to learn this relationship with acceptable accuracy. In most cases the validation loss dropped below 0.1 after only a couple of epochs. In one particular case, we even reached both mean and median errors lower than 0.2 for approximately 80% of the entire test set of 1600 examples using our methodology. From an application point of view, however, these low test set errors should be treated with caution since small deviations from the intended rotation matrix can cause volume warping and translation. In another case, in which we used a hold-out set, only a fraction of the median errors were below 0.2.

Intraindividual variance of lower limb rotation in patients with bilateral knee osteoarthritis

Purpose

To determine the side-to-side difference in intraindividual rotation alignment of patients with bilateral varus-type knee osteoarthritis (OA) and compare it with control subjects.

Methods

This retrospective study enrolled 60 patients with bilateral varus-type knee OA and 50 control subjects. All cases underwent bilateral lower limb CT angiography. Bilateral femoral and tibial rotation alignment were measured, and the overall lower limb rotation was calculated by two different methods. Method 1 was calculated by subtracting angle of the femoral torsion from the tibial torsion and method 2 was determined by relative rotation of the femoral neck angle to bimalleolar angle. The intraindividual variance and differences between the two groups were analyzed.

Results

Both OA and control samples showed significant differences between right and left for all measurements. Femoral torsion for control group was 10.4 ± 5.5°, tibial torsion was -22.1 ± 6.1°, and overall leg rotation by method 1 was -15.6 ± 7.2° and method 2 was -11.7 ± 8.2°. Femoral torsion, tibial torsion, method 1, and method 2 in the patients with OA were 8.2 ± 6.3°, -18.6 ± 4.1°, -14.9 ± 7.9°, and -10.4 ± 7.6°, respectively. Patients with OA showed a more pronounced retroversion in the femur (p = 0.008) and more internal rotation in the tibia (p < 0.001). No statistical significance of both methods was found between the two groups. Patients with OA had a greater median side-to-side absolute difference in all measurements, though the differences of both two methods of overall lower limb rotation were not statistically significant.

Conclusions

The discrepancy of side-to-side differences of bilateral lower limb rotation ought to be noticed with caution in diagnosing and treating rotational deformities of the lower limb, especially for patients with bilateral knee OA.